The present invention relates to a device for inserting an implant that can expand radially between a contracted state and a dilated state, the device being of the type comprising: a hollow support defining at least one opening for retaining the implant situated in the vicinity of the distal end thereof; and at least one threadlike link for retaining the implant. The link includes a control portion engaged in the support and a tightening loop connected to the control portion and intended to encircle the implant, with the tightening loop projecting outside the support through the retention opening.
Such a device is applicable for insertion into a blood vessel of a tubular endoprosthesis, widely referred to by the term “stent”, or of an endovalve comprising a tubular endoprosthesis and a valve fixed on the endoprosthesis.
A device of the above-mentioned type is disclosed in EP-A-0 707 462. An endoprosthesis is mounted coaxially on two hollow supports, which are capable of sliding in relation to each other. The endoprosthesis is held in the retracted state using threadlike links that encircle the ends thereof. The threadlike links are engaged respectively in the distal and proximal retention openings arranged respectively in one or the other of the supports.
To insert the endoprosthesis, the supports are moved by sliding relative to each other, so that the distance between the retention openings is reduced.
The reduction of this distance causes the threadlike links to loosen and consequently leads to the simultaneous deployment of both ends of the endoprosthesis.
Such a device is not entirely satisfactory. Indeed, given the complexity of the insertion device, loading of the endoprosthesis onto the device must be carried out in the factory during manufacture of the insertion device. Consequently, it is not possible for the surgeon to modify the size of the endoprosthesis mounted on the insertion device just before the operation, depending on the morphological characteristics of the patient. The surgeon must therefore provide, in the operating theatre, endoprostheses of varied dimensions to suit the morphology of the patient to be treated, which is expensive.
Moreover, if the endoprosthesis has a flexible valve, the valve must be kept in a physiological solution separate from the insertion device. It is therefore not possible to use such an insertion device with endovalves.
An object of the invention is therefore to obtain an insertion device comprising a support and at least one threadlike retention link forming a tightening loop of adjustable size, in which the expandable implant can easily be loaded onto the insertion device by the surgeon just before an operation.